The subject matter disclosed herein relates to turbomachines, and, more particularly, to an improved blade monitoring system for turbomachines.
Turbomachines include compressors and turbines, such as gas turbines, steam turbines, and hydro turbines. Generally, turbomachines include a rotor, which may be a shaft, drum, disk, or wheel to which turbomachine blades are attached. Turbomachines may include blade monitoring systems to monitor degradation of the turbomachine blades.
Existing blade monitoring systems may include magnetic pickup type transducers. However, magnetic pickup type transducers may be susceptible to various weaknesses. For example, magnetic probes can exhibit very low signal amplitude at low turbine blade speeds and very high signal amplitudes at high turbine blade speeds. Additionally, magnetic pickup probes are susceptible to, and also induce, magnetic fields. Furthermore, magnetic pickup probe performance may be degraded due to thermal or mechanical stresses, or both.